Jean meyer



PATENT FFICE.

JEAN or DUDELINGEN, GERMANY.

\METH' QD OF CARBUR IZING IRON.

, accordance with which molten pig iron or any SPECIFICATION formingpart of Letters Patent No. 524,904, dated August 21, 1894.

Application filedJnly 7,1894. Serial No. 616,832. (No specimens.)Patented in France November 8, 1890, No- 209,26Z; in England November 3,1890, No- 17,613, in Belgium November 3, 1890, No- 92,558; in LnxembnrgNovember 3, 1890,110.

1,371, and in Germany November 4, 1890, No. 74,419.

To aZZ whom it may concern..-

Be it known that I, JEAN MEYER, a subject of the Grand Duke ofLuxemburg,at present residing at Diidelingen, Luxemburg, Germany, haveinvented certain new and useful Improvementsin Methods for CarburizingIron, (for which I have obtained LettersPatent in France, No. 209,262,dated November 3, 1890; in GreatBr'itain, No. 17,613, dated November 3,1890 5 in Belgium, No. 92,558, dated November, 3, 1890; in Luxemburg,No.1,37 1, dated November 3,1890, and in Germany, No. 74,419, datedNovember 4, 1890,) of which the following is an exact description.

The present invention relates to a method in other ferruginous mixture(which has been converted or refined, and decarburized or decarburizedand dephosphorized, as the case may be, either in the Bessemer or thebasic converter, or in the Siemens-Martin furnace, or in the open hearthfurnace, &c.,) is subjected directly in the casting ladle to such acarburization by the introduction of a suitable carburizing substance,that any desired predetermined content of carbon may be obtained toproduce steel of any desired and predetermined degree of hardness.

The method consists in uniting the molten metal with briquets ofpulverized coal or coke and lime. In order to carry out this method, thecarburizing substance should be added in such a form that itmay bedissolved immediately and regularly, and also distributedregularlythroughout the whole mass of molten metal, and on the other hand, themoment for introducing the carburizing substance into the molten metalshould be so chosen that the reaction of the carburization is completelyterminated before pouring the metal from the ladle into the ingot molds.

The raw materials for the carburizing sub; stances are pulverized andcompressed into briquets, blocks or other forms, after having beenpreviously mixed with another-binding substance, which is at the sametime purifyin For the carbonaceous substances anthracite coal may beadvantageously employed on account of its purity, but coke will answer,and for the purifying and binding substance, hydrate of lime may beused, ,which should be as far as possible, exempt from inert matter. Thecarbonaceous substances are intimately mixed with the purifying andbinding matter and worked into a pasty mass, which is' allowed to standfor twelve to twenty-four hours before being compressed into blocks orbriquets. After the briquets are made they are first dried in the airand then in adrying chamber.

In order to make a pasty mass of, say, one hundred kilograms, I employabout seventysix kilograms of coal and about twenty-four kilogramsoflime, to form eighty-two kilograms of products. To produce ingot ironhaving a content of carbon from .04 per cent. to 0.1 per cent. ofcarbon, or medium steel with 0.1 per cent. to 0.4 per cent. of thatsubstance, the whole quantity of blocks or briquets made in the mannerdescribed above, is distributed over the bottom of the casting ladle,and then the metal is allowed to flow in a strong jet, care being takento move the ladle about so as to agitate the contents,'and to insure aregular dissolving of the carburizing substance throughout the wholemass of molten metal.

To produce hard steel with a content of carbon exceeding 0.4 per cent.-all the blocks or briquets are in a like manner introduced into thecasting ladle, but so that only part of them is present before the Howof metal into the casting ladlebegins, the remainder being added afterthe absorption of the first part, and this latter proportion being sodetermined as to introduce into the metal such a quantity of carbon asmay be necessary for impartingthe degree of hardness required. When thereaction, which does not require more than from three to five minutes,is completelyterminated in the casting ladle, the metal is poured intothe ingot mold, where it keeps quite still and does not rise in theslightest degree, so that perfectly soft ingots are obtained. Thequantity of briquets to be added depends upon the amount of carboninithe briquets, and on the desired degree of hardness intended to begiven to the steel to be manufactured.

Practical tests have shown that for converting a metric ton of pig ironinto ingot iron, or hard or mild steel, the following contents of carbonmust be added:

For ingot iron, 0.040 to 0.060 per cent. of carbon, one to 1.20kilograms of briquets; 0.060 to 0.100 per cent. of carbon, 1.20 to twokilograms of briquets.

For soft and hard steel, 0.10 to 0.15 per cent. of carbon 2.50 to2.80kilograms of briquets; 0.15 to 0.20 per cent. of carbon three to 3.50kilograms of briquets; 0.25 to 0.30per cent. of carbon four to 4.50kilograms of briquets; 0.30 to 0.35 per cent. of carbon five to 5.30

kilograms of briquets; 0.40 to 0.45 per cent.

of carbon seven to 7.50 kilograms of briquets; 0.45 to 0.50 per cent. ofcarbon 7.50 to 7.80 kilograms of briquets; 1.60 to'1.65 per cent. ofcarbon twenty. to twenty-five kilograms of briquets.

In this-process it is desirable to repeatedly test each charge beforepouring the metal into the ladle,so'as to obtain the accurate amount-ofthe carburizing material required for a certain degree of hardness ofthe desired product. By the process described, enough heat is generatedor'developed so that the ashes of the carburizing material are melted inthe ladle, and the silica containedin the asheschemically unites withthe lime contained as a binding material in the briquets, so that afluid slag is produced which unites with any other slag that may form,and this mass quickly separates from the molten metal and floats on thesurface thereof, the ashes thus acting as a purifier for the moltenmetal.

Experience shows that the content of sulphur in the carburized materialdiminishes to a considerable extent. By this method, steels have beenproduced with predetermined amounts of from 0.04 to 1.60 per cent. ofcarbon without the addition of ferro-manganese or spieg'eleisen. p

Having thus described my inventlon, I claim as new and desire to secureby Letters Patent 1. The herein-described method for the carburizationof iron, consisting'in uniting'the. molten metal with briquets of,pulverized coal

